Apple seeded Mavericks 10.9.5 build 13F14 to developers on Wednesday, just a little over a week after seeding build 13F12. Apple is asking developers to focus on USB, USB Smart Cards, Graphics, Safari, and Thunderbolt.
The new beta seed is available to developers via the “Update” tab in the Mac App Store, and via the Mac Developer Center.
(Via MacRumors)